1. Technical Field
The present invention relates to an apparatus and a method for preparing parts cut from a layup of sheet material and, more particularly, to optimization of matching and cutting operations therefor.
2. Background Art
A process for fabricating cloth products from web material includes a number of steps and utilizes complicated machinery. First, the web material is spread on a spreading table by a spreading machine. The cloth is typically spread one layer at a time to form a stack or a layup having a certain width and height. The stack is then moved to a cutter table. A conventional cutter table extends in a lateral or Y-axis direction and a longitudinal or X-axis direction and has a permeable bristle surface. A cutter head is typically movably attached to a cutter beam with the cutter beam being movable along the cutter table in the X-axis direction and with the cutter head being movable with respect to the cutter beam in the Y-axis direction.
Once the layup is moved to the cutter table, parts are cut by the cutter head according to a marker or a nest that outlines the shapes of the parts. The marker can also include parts that have either the same or different shapes. However, the individual parts in each layer will have the same shape as the part in the layer above or below. The cut parts are then sewn together at a later time.
Preparation of a marker or nest typically requires that complicated and often conflicting requirements are met. For greater efficiency, it is important to minimize wasted material when nest or marker are prepared. However, to ensure high quality of the final product, certain parts have to be cut to match other parts in the layup. This becomes especially critical when material has a pattern. In that event, certain parts have to be aligned precisely with others.
The process of matching parts in a layup has been partially automated. A camera is mounted onto the cutter beam to view the material to be cut. As the camera views the material, it also analyzes the pattern and provides data for modifying the nest or marker to ensure that the necessary parts with pattern are properly aligned. In current cutter systems, the camera is mounted on the opposite side of the cutter head in order to minimize interference between the cutter head and the camera""s field of view. As the camera and the cutter head are mounted on opposite sides of the cutter beam, an offset between the cutter tool and the camera is established.
The tool offset between the cutter tool and the camera presents a number of problems. One problem is that when the layup is moved onto the cutter table from the spreader table and the cutter beam is moved to the leading edge of the cutter table to start cutting operation, the camera cannot view and analyze the layup that is disposed within the tool offset between the cutter tool and the camera. Therefore, a smaller marker or nesting layout are generated such that the camera can visit all match points. Smaller marker usually results in less efficient use of material.
Another major shortcoming of the existing system is that the offset reduces usable area of the cutter table. Reduction in cutter table usable space is highly undesirable since the chance of matching all parts is reduced. If some parts that need to be matched are out of reach of the camera and the cutter head, then the cutter cannot proceed with the cutting operation. This requires an operator to manually attempt to match the necessary pieces. For the operator to successfully match various parts of the layup, the operator must be highly skilled and spend a great deal of time. The problem of fitting larger layups onto the cutter table is exacerbated by newer conveyorized tables. The conveyorized tables are much shorter than conventional cutter tables and include a much smaller conveyorized bristle surface. While the conveyorized tables save floor space in the shop and reduce size and cost of the expensive bristle surface, it is more difficult to match all the necessary pieces since much smaller layup can fit onto the table. Additionally, smaller usable area of the cutter table results in a greater number of layup to yield the same quantity of parts. This reduces efficiency of the operation.
Another drawback of the existing systems is that an origin for cutting instructions must be selected manually. Cutting data stored in a cut file requires that an origin or starting point on the layup be established. Currently, an operator must select the origin for the cutting operation to start. Typically, selection of the origin is a trial and error process that is time consuming and not always error free.
Therefore, it is desirable to reduce waste of sheet material and optimize the size of the layup that can fit and be cut on the cutter table.
It is an object of the present invention to optimize cutting and matching operations.
It is another object of the present invention to minimize waste of sheet material.
It is a further object of the present invention to optimize the size of the layup that can fit and be cut on the cutter table.
It is another object of the present invention to optimize matching of various pieces in the layup.
The present invention in one aspect is directed to a method for evaluating sheet-type work material that is carried on a cutting apparatus support surface to minimize waste. In the method, a cutting apparatus is provided that has a movable support on to which at least one layer of sheet-type work material can be placed. A camera and a cutter head are mounted to the cutting table such that the camera and cutter head can be moved to various locations above the movable support. The camera and cutter head are offset a distance relative one to the other defining an offset distance between a tip of the cutter head and a focal point of the camera. The camera""s movement over the support surface defines a scanable area, and the cutter head""s movement over the support surface defines a cuttable area within the scanable area. As a result of the offset distance, an ancillary area is created.
In the method, the work material is placed on the support surface. A portion of the work material is within the scanable area. The camera is then placed over the work material at a selected origin point. The camera commencing from the selected origin point then scans at least part of the portion of the work material generating a first set of data. The moveable support then relocates the work material such that at least some of the part of the work material corresponding with the first set of data is within the ancillary area. The camera then scans at least some additional work material within the cuttable area to generate a second data set. Using the first and second data sets, a cutting operation is then performed in both the cuttable area as well as the ancillary area.
According to the present invention, an apparatus for cutting and matching individual parts in a layup of material includes a cutter table extending in a longitudinal direction from a take-on end to a take-off end for supporting the layup, a conveyor belt mounted onto the cutter table for advancing the layup from the take-on end to the take-off end of the cutter table, a cutter beam movable in the longitudinal direction along the cutter table, a cutter head mounted onto the cutter beam, a camera disposed on the cutter beam at an offset from the cutter head to define a tool offset, and a computer including instructions for optimizing a process for matching various parts in the layup resulting in an increase of effective usable area of the cutter table and in increased efficiency in use of material in the layup.
The camera of the present invention is directed to process match points that are disposed within the tool offset prior to advancing the layup to the take-off end of the cutter table. The camera extracts the matching points for the parts to be matched from a data file according to the X-coordinate positions and processes those match points with X-axis values less than the tool offset prior to advancing the conveyor.
The apparatus and method of the present invention allow more efficient use of material and also increase usable area of the cutter table.
The foregoing and other advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.